Message-ID: <52DA3E41.9050202@huawei.com>
Date: Sat, 18 Jan 2014 16:41:37 +0800
From: Jianguo Wu <wujianguo@huawei.com>
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To: Catalin Marinas <catalin.marinas@arm.com>
CC: Andrew Morton <akpm@linux-foundation.org>,
        "rob@landley.net" <rob@landley.net>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Li Zefan <lizefan@huawei.com>, Wang Nan <wangnan0@huawei.com>
Subject: Re: [PATCH] mm/kmemleak: add support for re-enable kmemleak at runtime
References: <52D8FA72.8080100@huawei.com> <20140117120436.GC28895@arm.com>
In-Reply-To: <20140117120436.GC28895@arm.com>
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Sender: linux-kernel-owner@vger.kernel.org

On 2014/1/17 20:04, Catalin Marinas wrote:

> On Fri, Jan 17, 2014 at 09:40:02AM +0000, Jianguo Wu wrote:
>> Now disabling kmemleak is an irreversible operation, but sometimes
>> we may need to re-enable kmemleak at runtime. So add a knob to enable
>> kmemleak at runtime:
>> echo on > /sys/kernel/debug/kmemleak
> 
> It is irreversible for very good reason: once it missed the initial
> memory allocations, there is no way for kmemleak to build the object
> reference graph and you'll get lots of false positives, pretty much
> making it unusable.
> 

Do you mean we didn't trace memory allocations during kmemleak disable period,
and these memory may reference to new allocated objects after re-enable? 

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